When the state's new health insurance marketplace posted premium rates last fall, southeast Minnesota stood out as the region with the highest costs and fewest coverage options.

State lawmakers from Faribault to Winona want to change that. They're already hearing warnings, however, from insurers and doctors that tinkering with state rules that dictate how much insurance can cost and how distant doctors can be from their patients could drive health plans from the market and hurt care.

A big reason rates are so much higher in southeast Minnesota is because of the Rochester-based Mayo Clinic. The facility is world renowned for its high quality care, but the cost of that care drives up insurance prices across the region. It's expensive for insurers to enter that market, which means fewer plans to choose from, health care policy experts say.

Southeast Minnesota shouldn't have to bear that burden alone, said Rep. Tina Liebling, DFL-Rochester, who is the chief sponsor of a bill that lays out an array of proposals that would make insurance in her area less expensive. The bill proposes redrawing the geographical boundaries used to calculate the cost of a health insurance policies and capping some premiums.

Those changes would make premiums cheaper in high-cost parts of the state, but more expensive in relatively low cost parts of the state, like the Twin Cities.

All Minnesotans benefit from Mayo, Liebling argues. It's an economic driver for the state and trains many doctors here, so its costs shouldn't fall heavier on southeast Minnesota.

"Mayo is there as a resource for the entire state," she said. "If local people pay higher rates because the higher costs are baked into our rates, where's the fairness in that?"

Mayo says that it treats patients with difficult illnesses and does a lot of research, too.

"We're not a community-based hospital. This is an academic medical center that does research, education and top-of-the pyramid care for the sickest of the sick," Mayo's government relations chair Kathleen Harrington told MPR News last fall. "The cost is naturally higher."

Lawmakers who oppose the bill say it isn't fair for people in the rest of the state to subsidize costs in southeast Minnesota.

Scott Keefer, who is vice president of policy and legislative affairs for Blue Cross and Blue Shield of Minnesota, says it's a bad idea to change the state's insurance rating areas, which were required by the Affordable Care Act as part of a larger effort to narrow what factors insurance companies can use when setting policy prices.

"One of the goals of the ACA was to ensure that health plan competition is based on price, service and quality," said Keefer. "If we're establishing the rules based on something other than that, there's presumably less transparency."

These provisions would discourage insurance companies from offering coverage in Rochester, where choice is already limited to two companies.

"This would be self-defeating, counter-productive proposal that would very likely drive Medica and Blue Cross out of Rochester," said health care policy expert and University of Minnesota professor Roger Feldman.

Another part of Liebling's bill would let people pay less for a health care policy that covers facilities farther away.

Lower income customers will likely choose the less expensive plan, but getting care could mean driving great distances, said Dave Renner, director of state and federal legislation for the Minnesota Medical Association.

"I would argue that that's the type of choice you may not want to provide," Renner said in a recent hearing on the bill. "That may be coverage, but it doesn't really provide you access to care."

Politically speaking, Liebling says her bill might be a tough sell to colleagues who represent constituents outside her region. She views it as a starting point.

"I thought it was worth having a conversation about why there are rate disparities in the state and what approaches we might take to that," she said.